This invention relates to expansible shafts.
Such shafts have an axially extending housing and a core engager which moves radially from a retracted position within the housing to an expanded position in which the core engager extends beyond the outer housing wall. For example, Peterson U.S. Pat. No. 4,254,920 (assigned to the assignee of this application) discloses a fluid-actuated shaft having an operating rod that is mounted co-axially with and moves axially relative to the housing. Springs move the actuators to force the core-engagers radially outwardly into engagement with a surrounding core and a fluid-activated piston drives the operating rod in the other direction to retract them.
One system for coupling the rod and core engagers is shown in, and described with reference to, FIGS. 6-9 of the related applications of Messrs. Pontes, Flagg and Young cited hereinafter. As there shown, the core engagers are attached to radially extending cam-followers which terminate in cam-follower surfaces that are inclined with respect to the shaft axis. The actuator has cam surfaces parallel to, and in contact with the follower surfaces. Rolled steel pins extend through lateral openings to bores in the cam followers and engage grooves in the actuators parallel to the cam surfaces. This arrangement has proved to present practical operational problems; in particular it has not proved as strong as desirable and has been difficult to disassemble for repair.